A Public Warning System (PWS) provides public warning services to users. The PWS is comprises of two parts, i.e., an Earthquake and Tsunami Warning System (ETWS) and a Commercial Mobile Alert System (CMAS). The ETWS warning system notifies people that the earthquake and tsunami will come soon or of disaster relief information after the earthquake and tsunami disasters (such as notification of shelter locations); and the CMAS provides public security alert services (such as forest fires, terrorist attacks, etc.) to end users. Users who receive the alerts take actions according to the contents of the alerts to protect their life and property safety. The current mobile phone is a medium closest to people, and the PWS aids people in avoiding disasters or reducing losses due to disasters using such characteristics.
The Long Term Evolution (LTE) system transmits an ETWS primary notification through a SystemInformationBlockType10 (SIB10), an ETWS auxiliary notification through SystemInformationBlockType11 (SIB11) and a CMAS alert information through SystemInformationBlockType12 (SIB12); wherein the ETWS auxiliary notification and the CMAS alert need to be divided into a number of segments and then be respectively transmitted through the SIB11 and the SIB12 due to a long length of the message. The SIB12 transmits contents of a number of CMAS alert messages, which are transmitted at different times. In the transmission process, SIB12 segments for different alerts are not allowed to be overlapped, i.e., only after all SIB12 segments of one alert are transmitted completely, SIB12 segments of the next CMAS alert information can be transmitted. The SIB 11 is similar to the SIB12, and the difference therebetween is that the SIB12 transmits multiple CMAS alerts, and the SIB11 only transmits one ETWS warning.